By Ahmad Ghaddar and Alex Lawler

LONDON/MOSCOW (Reuters) -OPEC+ will likely stick to its planned increase in oil output for February when it meets on Tuesday, four sources from the group told Reuters, as it expects the Omicron coronavirus variant to have a short-lived impact on demand.

OPEC+, which groups producers from the Organization of the Petroleum Exporting Countries (OPEC) with others including Russia, has raised its output target each month since August by 400,000 barrels per day (bpd).

"OPEC+ will have an easy meeting without any problems today and will reaffirm the previous agreement," an OPEC+ source said. Three other OPEC+ source echoed that view.

The full OPEC+ meeting is scheduled to start at 1300 GMT. The Joint Ministerial Monitoring Committee, which can make a recommendation to the full group, convenues at 1200 GMT. Both meetings are virtual.

OPEC+ is unwinding record production cuts of 10 million bpd that were made in 2020 as demand and prices recover from their pandemic-induced slump. Last year, Brent crude rose 50% and it has rallied so far in 2022, trading above $79 on Tuesday. [O/R]

Current plans would see OPEC+ again raise the target by 400,000 bpd for February, leaving about 3 million bpd in cuts to unwind by September in line with an agreement reached last July.

In a technical report seen by Reuters on Sunday, OPEC+ played down the impact on demand from the Omicron variant, saying it would be "mild and short-lived" and was upbeat about economic prospects.

"This is in addition to a steady economic outlook in both the advanced and emerging economies," the Joint Technical Committee report said.

While OPEC+ has increased its output target each month, actual production has lagged as some members struggle with capacity constraints.

OPEC+ producers missed their targets by 730,000 bpd in October and by 650,000 bpd in November, the International Energy Agency said last month. [IEA/M]